I have been motoring for 38 years on vehicles of varying descriptions, beginning with a McKenzie Hobart belt-driven motorcycle, most of which -I put it kindly – were well run-in when I bought them.
I have never yet changed oil in any engine other than at a necessary overhaul. Only twice have I been stopped on the road with actual engine failure. A seized engine on a 250 round-tank B.S.A. and a broken valve in a Panthette motorcycle. At no time has any car engine let me down.
The makers of the only oil I have ever used, Castrol, must have unwittingly been producing long-life oil for many years.
I, of course, have no connection, nor has persuasion, gentle or otherwise, been exerted, etc.